Always ethereal, always eclectic, I write as the mood strikes, when there intrigue reveals itself. Usually that means something controversial or adventure of some sort.

I've tried really hard to be unprovocative, but have as yet been unsuccessful.

Friday, 30 January 2009

Choosing Life, in All It's Wonder

Many years ago, I read a book by the Great One, Stephen Jay Gould, called Wonderful Life. It was all about the Burgess Shale, a place in Canada with the largest collection of fossils on the planet from the Cambrian Explosion. The Cambrian Explosion is significant because some 530 million years ago, which saw the largest explosion of life in the greatest diversity, ever. There were organisms with life plans like nothing you've ever seen. Some were arthropods that are nothing like arthropods today. Many were whole phyla that have gone extinct. Gould's point was that nearly all life is now extinct, and that the truly weird life plans no longer exist. And my favorite example of this was Hallucigenia, a stick walking on five long tubes, with a double row of spines sticking out on top, and five eyes on a bulbous head. Truly worthy of Owsley.Imagine my joy then, on finding out that there was a collection of the Burgess Shale fossils right here in my city! And today, I finally made the opportunity to visit the UW Madison Geology Museum.

Just outside the museum is an oceanography department, whose most salient feature is a very cool map of the current weather on the planet.

There's also a bunch of rocks and meteorites at the Geology Museum. I was eager to get to the fossils, so I only stopped by the phosphorescent rocks. (And now were back to the acid.)

Then, on to the fossils. The museum actually begins with the oldest of the old, the Stromatolites, the very first fossils: algal mats from 3.5 bya- that's a b for billion, and only a mere billion years after our planet began. This is significant because it shows that life isn't all that difficult to begin. Our planet formed from a ball of gas and dust, cooled down, formed oceans, began life, and then formed life that could actually fossilize, all in only a billion years, a quarter of the planet's lifespan. The formation of life isn't all that amazing, history would tell us. Rather, it's the formation of multicellular life that took some time.

One of my two favorite phyla is Cnidera, one of the simplest, with only two cell layers. Most Cnideria fossils are coral. It's rare to find jelly fossils, like these below.

Most though not all fossils in the museum come from Wisconsin. Here are some delightful gigantic cephalopods from ancient times.

And then, what I had been eagerly anticipating, the collection from the Burgess Shale.It began with Pikaia gracilens, found in the Burgess Shale, and may perhaps be the earliest Chordate ever found- what our ancestor looked like.

I was particularly delighted to see some specimens I recognized from the book, including Marella splendens.When I was teaching biology, every year I would trot out overheads of the Burgess Shale animals for the students to see. One point I wanted them to get was the same that Gould stressed: the process of discovery in science. When the Burgess Shale were first discovered, we found a strange animal that looked like a flat marine jelly.

Another looked like parts of the typical shrimp.And then, they realized that the jelly was actually a mouth, and the shrimps were the tentacles, all of one organism- Anomolocaris, a veritable fossil Frankenstein. The complete animal is pictured below.

Just beyond the Burgess Shale was the Echioderm display, my other favorite phylum. (Hey, I have a thing for radially symmetric animals with nerve nets.) Most of the fossils were that class that every one forgets about- the Crinoids - the sea lillies. To the right is a fossil bed of them. Below is Crinoid Limestone.

Beyond the invertebrates I came to our phylum. The Xiphinactus predatory fish, a fish fossilized in the act of eating another fish, and an ancient rhino.

Someone at the museum has a bit of a macabre sence of humor. In the same enclosure, facing each other, was a three-toed horse and a young sabertooth cat.

Towards the end, I arrived at some very great delights. I found some of my favorite organisms- ancient giant pigs (above),and when I glanced up, I was surprised to find a Mosasaur and Pteranodon swimming above. And then, an inventory sign, and a thought I hadn't previously contemplated. Darwin Day is coming up on the 12th, the celebration of the 200th anniversary of the birth of the greatest biologist in history. As of the Darwin Day celebrations on the 7th, I'll be working towards being a volunteer tour guide at the museum, and getting to work with the ancient organisms I love.

6 comments:

Did you take Prothero's Historical Geology class? I really *loved* all this stuff. What a dream and a joy! I fear that I may have somehow thrown out the fossils I collected on the field trip for that course :(

If you ever make it to Cambridge England DO NOT MISS Sedgwick's Museum of Geology. Oh my, I swear it must be the holiest place in all of England, a veritable church of Evolution. Wow.

If you've never read Bill Bryson's "A Short History of Nearly Everything" you'd probably really appreaciate it right now!

To my regret to this day, I never took his class on paleontology (if that's the same class). I was planning to, till my senior year, and felt like I was being lead in a different direction. So I just took the Intro Geo course with him, and then recently read his excellent book on Fossils.

I knew you weren't in Historical with me (more than just Paleo, because we also studied the tectonic events and stratigraphy of each time period), because I don't remember you on the field trip. Haven't read his book yet; thanks for hte reminder!